FEMALE-BIASED SEX RATIOS: INDIVIDUAL OR GROUP SELECTION?
نویسندگان
چکیده
منابع مشابه
Sexual selection favors female-biased sex ratios: the balance between the opposing forces of sex-ratio selection and sexual selection.
In a verbal model, Trivers and Willard proposed that, whenever there is sexual selection among males, natural selection should favor mothers that produce sons when in good condition but daughters when in poor condition. The predictions of this model have been the subject of recent debate. We present an explicit population genetic model for the evolution of a maternal-effect gene that biases off...
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PREMISE OF THE STUDY The development of biased sex ratios in dioecious plant species has been ascribed to either (1) factors influencing differential adult mortality of male and female plants or (2) factors acting at an early life stage that determine seed sex ratio or seedling survival. METHODS To discriminate between these two competing hypotheses, we surveyed sex and age of 379 individuals...
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It has been recognized for some time that the risk of producing maleless clutches should select for a lower than binomial variance in the sex ratio of organisms with female-biased sex ratios, small clutches and breeding groups containing the clutch of a single female. However, to date, precise sex ratios have only been reported for organisms with haplodiploid sex determination, a system which a...
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The sex ratio behavior of parasitoid wasps in the genus Melittobia is scandalous. In contrast to the prediction of Hamilton's local mate competition theory, and the behavior of numerous other species, their extremely female-biased sex ratios (1-5% males) change little in response to the number of females that lay eggs on a patch. We examined the mating structure and fitness consequences of adju...
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Social insect sex and caste ratios are well-studied targets of evolutionary conflicts, but the heritable factors affecting these traits remain unknown. To elucidate these factors, we carried out a short-term artificial selection study on female caste ratio in the ant Monomorium pharaonis. Across three generations of bidirectional selection, we observed no response for caste ratio, but sex ratio...
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ژورنال
عنوان ژورنال: Evolution
سال: 1985
ISSN: 0014-3820
DOI: 10.1111/j.1558-5646.1985.tb05672.x